The Soviet Union has canceled plans to construct two new reactors at the stricken Chernobyl nuclear power station and has halted plans to expand all other similar plants, the Tass news agency said Thursday.

The decision was announced six days before the third anniversary of the Chernobyl accident that killed 31 people in the world's worst civilian nuclear disaster.Plans to construct two additional reactors at the facility had been suspended since the explosion of the No. 4 reactor spread a cloud of radiation over eastern Europe April 26, 1986.

Addition of No. 5 and No. 6 reactors to the four-reactor plant would have made it the biggest atomic station in the world, supplying the energy needs of the Ukraine as well as of Eastern Europe.

"The Council of Ministers has adopted an unequivocal decision to abandon the construction of the fifth and sixth power blocks of the Chernobyl nuclear power station on which work had been suspended after the Chernobyl accident," Tass said.